 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.filebuffers.manipulation;

 import org.eclipse.core.internal.filebuffers.FileBuffersPlugin;
 import org.eclipse.core.internal.filebuffers.Progress;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.OperationCanceledException;
 import org.eclipse.core.runtime.Status;

 import org.eclipse.core.filebuffers.IFileBufferStatusCodes;
 import org.eclipse.core.filebuffers.ITextFileBuffer;

 import org.eclipse.text.edits.ReplaceEdit;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.DocumentRewriteSessionType;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;

 /**
  * A text file buffer operation that changes the line delimiters to a specified
  * line delimiter.
  *
  * @since 3.1
  */
 public class ConvertLineDelimitersOperation extends TextFileBufferOperation {

     private String fLineDelimiter;

     /**
      * Creates a new line delimiter conversion operation for the given target
      * delimiter.
      *
      * @param lineDelimiter the target line delimiter
      */
     public ConvertLineDelimitersOperation(String lineDelimiter) {
         super(FileBuffersMessages.ConvertLineDelimitersOperation_name);
         fLineDelimiter= lineDelimiter;
     }

     /*
      * @see org.eclipse.core.internal.filebuffers.textmanipulation.TextFileBufferOperation#computeTextEdit(org.eclipse.core.filebuffers.ITextFileBuffer, org.eclipse.core.runtime.IProgressMonitor)
      */
     protected MultiTextEditWithProgress computeTextEdit(ITextFileBuffer fileBuffer, IProgressMonitor progressMonitor) throws CoreException {
         IDocument document= fileBuffer.getDocument();
         int lineCount= document.getNumberOfLines();

         progressMonitor= Progress.getMonitor(progressMonitor);
         progressMonitor.beginTask(FileBuffersMessages.ConvertLineDelimitersOperation_task_generatingChanges, lineCount);
         try {

             MultiTextEditWithProgress multiEdit= new MultiTextEditWithProgress(FileBuffersMessages.ConvertLineDelimitersOperation_task_applyingChanges);

             for (int i= 0; i < lineCount; i++) {
                 if (progressMonitor.isCanceled())
                     throw new OperationCanceledException();

                 final String delimiter= document.getLineDelimiter(i);
                 if (delimiter != null && delimiter.length() > 0 && !delimiter.equals(fLineDelimiter)) {
                     IRegion region= document.getLineInformation(i);
                     multiEdit.addChild(new ReplaceEdit(region.getOffset() + region.getLength(), delimiter.length(), fLineDelimiter));
                 }
                 progressMonitor.worked(1);
             }

             return multiEdit.getChildrenSize() <= 0 ? null : multiEdit;

         } catch (BadLocationException x) {
             throw new CoreException(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, IFileBufferStatusCodes.CONTENT_CHANGE_FAILED, "", x)); //$NON-NLS-1$
 } finally {
             progressMonitor.done();
         }
     }

     /*
      * @see org.eclipse.core.filebuffers.manipulation.TextFileBufferOperation#getDocumentRewriteSessionType()
      */
     protected DocumentRewriteSessionType getDocumentRewriteSessionType() {
         return DocumentRewriteSessionType.SEQUENTIAL;
     }
 }

